Is it very easy to create a false jurisdiction for 498a

Yes this routinely happens, false jurisdiction is created by levelling such allegations. Even the Supreme Court in a recent decision has said that since cruelty is a continuing offence - and cruelty is meted out to a girl even when she returns back to her house - the place of parental residences acquires jurisdiction. Quite opposite to this is another SC decision - in Y.Abraham AJith.. 

Jurisdictions is a matter of facts and it is for the Judge to decide the jurisdictional aspects, and the judge should not allow any one to make a fool of the judge. As regard your brother joining the Govt job, I am of the view that unless the court prove him guilty of any offence with cogent evidence, his appointment or promotion can not be affected. Should the Government of India refrain from appointing Home Minister Shri.Chidambaram, as Finance Minister, just because his case 2 G scam is pending? The answer is a big NO, and I have voted NO in the forum poll.

False jurisdiction can be created easily by levelling a false allegation as to show that the incident took place within the jurisdiction of a particular magistrate. HC can quash an FIR if false jurisdiction is proved.